Question

If she solved this equation for s which of the following equations did she write

Answer 1

Explanation

What we basically need to do is solving the following equation for S:

$A=\frac{\pi r^2S}{360}$

This means that we must rewrite it in the form "S = something". We can start by multiplying both sides of the equation by 360:

$\begin{gathered} A\cdot360=\frac{\pi r^{2}S}{360}\cdot360 \\ 360A=\pi r^2S \end{gathered}$

Then we can divide both sides by pi:

$\begin{gathered} \frac{360A}{\pi}=\frac{\pi r^2S}{\pi} \\ r^2S=\frac{360A}{\pi} \end{gathered}$

And then we divide both sides by the square of r:

$\begin{gathered} \frac{r^2S}{r^2}=\frac{\frac{360A}{\pi}}{r^2} \\ S=\frac{360A}{\pi r^2} \end{gathered}$